Quantification of concurrence via weak measurement



: Tukiainen M, Kobayashi H, Shikano Y

Publisher: AMER PHYSICAL SOC

: 2017

: Physical Review A

: PHYSICAL REVIEW A

: PHYS REV A

: ARTN 052301

: 95

: 5

: 6

: 2469-9926

: 2469-9934

DOI: https://doi.org/10.1103/PhysRevA.95.052301

: https://research.utu.fi/converis/portal/detail/Publication/20686998


Since entanglement is not an observable per se, measuring its value in practice is a difficult task. Here we propose a protocol for quantifying a particular entanglement measure, namely, concurrence, of an arbitrary two-qubit pure state via a single fixed measurement setup by exploiting so-called weak measurements and the associated weak values together with the properties of the Laguerre-Gaussian modes. The virtue of our technique is that it is generally applicable for all two-qubit systems and does not involve simultaneous copies of the entangled state. We also propose an explicit optical implementation of the protocol.

Last updated on 2024-26-11 at 15:44